We propose to study the brain bases of one of the most basic aspects of social cognition, face processing. Parallel studies utilizing event-related potentials (ERPs) and functional magnetic resonance imaging (fMRI) will provide information about abnormalities in the timing and regional distribution of brain response to faces in autism. Twenty-five adults with idiopathic autism and 25 IQ- and age-matched typical individuals will participate in each study. These studies will examine ERP and flVIRI in response to face vs. nonface visual stimuli, to specific face parts (eyes vs. mouths), to moving vs. static face parts, and to familiar vs. unfamiliar faces. Separate eye-tracking studies on the same individuals will examine eye movements during viewing of different types of face stimuli. We will test a novel hypothesis that abnormalities in face processing in autism are related to atypical attentional strategies when viewing faces. Results of the ERP, fMRI, and eye-tracking studies will also be correlated with performance on neuropsychological tests of face perception and memory, and behavioral measures of social impairment. These studies will shed light on the nature and neural bases of face processing impairments in autism. Such information is clinically important for early identification, development of targeted interventions, and investigation of the genetic basis of autism. There is strong evidence of a genetic component in autism, and we expect that this research will lead to more refined measures of quantitative traits that can be used in genetic studies.